Engine generator sets are used in countless applications where a ready source of electrical power is either inconvenient or unavailable. These sets are often used at constructions sites or outdoors where adverse weather conditions are unpredictable or unavoidable. Engine generator sets are also often used as a backup electrical power source. In these types of conditions a loss of electrical power due to the failure of the engine generator set can result in a significant loss. Therefore, reliability of the components is extremely important.
A typical portable engine generator set consists primarily of a gas or diesel internal combustion engine that drives an alternator to generate electricity. Various electronic and mechanical controls necessary for operating the engine and regulating the electrical power generation are necessary components of a completely portable system.
A housing surrounding the engine generator set is often used to reduce the noise created by the operating system, protect users from coming into contact with heated parts, and protect the engine generator from adverse weather conditions. By enclosing the heat generating components, such as the internal combustion engine and alternator, with heat sensitive components, such as the starting battery and electrical controls, serious reliability issues arise.
In addition, using an air cooled engine for small enclosed standby engine generator sets is very cost effective compared to a liquid cooled engine. Using an air cooled engine, however, creates significant design issues related to purging the housing of the air rejected from an air cooled engine. Another significant design issue is to prevent the hot engine cooling air from recirculating back into the engine air intake and areas containing heat sensitive components.
Accordingly, it is desirable to have a cooling system for air cooled engine generator sets that provides cooling air paths that cool the hot components without heating the heat sensitive components of the engine generator set. Such a system is desirable when it does not increase the size or cost of the housing and further muffles the sound from the engine generator set.
U.S. Pat. No. 3,566,142 to Dabel issued Feb. 23, 1971; U.S. Pat. No. 4,243,893 to Sten issued Jan. 6, 1981; U.S. Pat. No. 4,495,901 to Nannini et al. issued Jan. 29, 1985; U.S. Pat. No. 4,608,946 to Tanaka issued Sep. 2, 1986; U.S. Pat. No. 4,647,835 to Fujikawa issued Mar. 3, 1987; U.S. Pat. No. 4,835,405 to Clanceu et al. issued May 30, 1989; U.S. Pat. No. 4,907,546 to Ishii et al. issued Mar. 13, 1990; U.S. Pat. No. 5,374,866 to Gill et al. issued Dec. 20, 1994; U.S. Pat. No. 5,515,816 to Ball et al. issued May 14, 1996; U.S. Pat. No. 5,624,589 to Latvis et al. issued Apr. 29, 1997; and U.S. Pat. No. 5,642,702 to Kouchi et al. issued Jul. 1, 1997 disclose countless different configurations and generators with enclosures and fans for drawing cooling air through the enclosure. The present invention provides solutions to these problems that are novel and advantageous over the prior art.